docs: def _search_mapred_emu(self, index, query):
          """
          Emulates a search request via MapReduce. Used in the case
          where the transport supports MapReduce but has no native
          search capability.
          """
          phases = []
          if not self.phaseless_mapred():
              phases.append({'language': 'erlang',
                             'module': 'riak_kv_mapreduce',
                             'function': 'reduce_identity',
                             'keep': True})
          mr_result = self.mapred({'module': 'riak_search',
                                   'function': 'mapred_search',
                                   'arg': [index, query]},
                                  phases)
          result = {'num_found': len(mr_result),
                    'max_score': 0.0,
                    'docs': []}
          for bucket, key, data in mr_result:
              if u'score' in data and data[u'score'][0] > result['max_score']:
                  result['max_score'] = data[u'score'][0]
              result['docs'].append({u'id': key})
          return result